Now you can start your next AR build right with the GGP MKII Billet AR-15 Builder's Set! Includes a GGP MKII Billet Receiver Set, GGP MKII Handguard. MKII Billet Receiver Set: The MKII Billet receiver set brings a new level of customizability never before seen in the rifle receivers. Not only can you build your own version of the GGP-S Light rifle, but you can use your favorite aftermarket parts to complete the weapon of your dreams. GGP Billet Receivers are precisely machined from 7075-T6 Aluminum for a perfect fit. The lower receiver includes the ambidextrous bolt release as a standard feature, as well as a flared magwell and integral trigger guard. Start your build off right.